From Cppreference
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| template< class T > class numeric_limits;
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The numeric_limits class template provides a standardized way to query about various properties of representation of fundamental types. This information is provided via specializations of the numeric_limits template. Specializations for fundamental types are already provided:
template<> class numeric_limits<bool>;
template<> class numeric_limits<char>;
template<> class numeric_limits<signed char>;
template<> class numeric_limits<unsigned char>;
template<> class numeric_limits<wchar_t>;
template<> class numeric_limits<char16_t>; //C++11 feature
template<> class numeric_limits<char32_t>; //C++11 feature
template<> class numeric_limits<short>;
template<> class numeric_limits<unsigned short>;
template<> class numeric_limits<int>;
template<> class numeric_limits<unsigned int>;
template<> class numeric_limits<long>;
template<> class numeric_limits<unsigned long>;
template<> class numeric_limits<long long>;
template<> class numeric_limits<unsigned long long>;
template<> class numeric_limits<float>;
template<> class numeric_limits<double>;
template<> class numeric_limits<long double>;
[edit] Members
| Member
| Default
| Explanation
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| static const bool is_specialized
| false
| true for all specializations of numeric_limits class template
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| static const bool is_iec559
| false
| true if the type adheres to IEC559 international standard (the same as IEEE 754). Meaningful for all floating point numbers.
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| static const bool is_signed
| false
| true if the type is signed
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| static const bool is_integer
| false
| true if the type is integer
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| static const bool is_exact
| false
| true if the type uses an exact representation
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| static const bool is_modulo
| false
| true if the type is modulo, i.e. if an operation consisting from *, + and - results in overflow then the final result differs from expected result by a multiple of integer (max() - min() + 1)
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| static const bool is_bounded
| false
| true if the type uses has infinite set of representable values, i.e. arbitrary precision number
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[edit] Representable values
| Member
| Default
| Explanation
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| static T min()
| {return T();}
| minimum finite value. For floating point types: minimum denormalized value. Only meaningful if is_bounded == true
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| static T max()
| {return T();}
| maximum finite value. Only meaningful if is_bounded == true
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| static T lowest() (C++11)
| {return T();}
| minimum finite value. Only meaningful if is_bounded == true
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| static const denorm_style has_denorm
| denorm_absent
| denorm_present if denormalized values are allowed, denorm_absent if not and denorm_indeterminate if this is not known at compile time. Meaningful for floating point types.
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| static T denorm_min()
| {return T();}
| returns minimum positive denormalized value. If has_denorm == denorm_absent, returns minimum positive normalized value. Meaningful for floating point types.
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| static const bool has_infinity
| false
| true if the type can represent positive infinity. Shall be true for all specializations in which is_iec559 == true
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| static T infinity()
| {return T();}
| returns positive infinity. Only meaningful if has_infinity == true. Required for all specializations in which is_iec559 == true
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[edit] Representation
| Member
| Default
| Explanation
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| static const int radix
| 0
| base of the representation
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| static const int min_exponent
| 0
| minimum negative integer such that radix raised by power one less than that integer is a normalized floating point number. Meaningful for floating point types
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| static const int min_exponent10
| 0
| minimum negative integer such that 10 raised by that power is a normalized floating point number. Meaningful for floating point types
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| static const int max_exponent
| 0
| maximum integer such that radix raised by power one less than that integer is a representable finite floating point number. Meaningful for floating point types
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| static const int max_exponent10
| 0
| maximum integer such that 10 raised by that power is a representable finite floating point number. Meaningful for floating point types
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[edit] Precision
| Member
| Default
| Explanation
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| static const int digits
| 0
| number of base radix digits that can be represented without losing precision
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| static const int digits10
| 0
| number of decimal digits that can be represented without losing precision. Only meaningful if is_bounded == true
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| static const int max_digits10
| 0
| number of decimal digits needed to represent any value without losing precision
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| static const T epsilon()
| {return T();}
| the difference between 1.0 and the next representable value. Meaningful for all floating point types
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| static const T round_error()
| {return T();}
| maximum possible rounding error
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| static const bool has_denorm_loss
| false
| true if loss of precision is detected as a denormalization loss, rather than as an inexact result
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| static const float_round_style round_style
| round_towards_zero
| floating point rounding mode. Meaningful for floating point types. Integer types shall return round_towards_zero
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[edit] Not-a-numbers (NaNs)
| Member
| Default
| Explanation
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| static const bool has_signaling_NaN
| false
| true if the type can represent signaling not-a-number (NaN). Shall be true if is_iec559 == true
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| static const bool has_quiet_NaN
| false
| true if the type can represent non-signaling (quiet) not-a-number (NaN). Shall be true if is_iec559 == true
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| static T signaling_NaN()
| {return T();}
| returns signaling not-a-number (NaN). Only meaningful if has_signaling_NaN == true. Required if is_iec559 == true
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| static T quiet_NaN()
| {return T();}
| returns non-signalling (quiet) not-a-number (NaN). Only meaningful if has_quiet_NaN == true. Required if {{{1}}}
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[edit] Miscellaneous
| Member
| Default
| Explanation
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| static const bool traps
| false
| true if it is possible for trap to happen
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| static const bool tinyness_before
| false
| true if tinyness is detected before rounding. Meaningful for floating point types.
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[edit] Relationship with macro constants of C library
| Specialization
| Members
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| min()
| lowest()
(C++11)
| max()
| epsilon()
| digits()
| digits10()
| min_exponent()
| min_exponent10()
| max_exponent()
| max_exponent10()
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| numeric_limits< bool >
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| numeric_limits< char >
| CHAR_MIN
| CHAR_MIN
| CHAR_MAX
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| numeric_limits< signed char >
| SCHAR_MIN
| SCHAR_MIN
| SCHAR_MAX
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| numeric_limits< unsigned char >
| 0
| 0
| UCHAR_MAX
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| numeric_limits< wchar_t >
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| numeric_limits< char16_t >
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| numeric_limits< char32_t >
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| numeric_limits< short >
| SHRT_MIN
| SHRT_MIN
| SHRT_MAX
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| numeric_limits< signed short >
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| numeric_limits< unsigned short >
| USHRT_MIN
| USHRT_MIN
| USHRT_MAX
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| numeric_limits< int >
| INT_MIN
| INT_MIN
| INT_MAX
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| numeric_limits< signed int >
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| numeric_limits< unsigned int >
| 0
| 0
| UINT_MAX
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| numeric_limits< long >
| LONG_MIN
| LONG_MIN
| LONG_MAX
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| numeric_limits< signed long >
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| numeric_limits< unsigned long >
| 0
| 0
| ULONG_MAX
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| numeric_limits< long long >
| LLONG_MIN
| LLONG_MIN
| LLONG_MAX
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| numeric_limits< signed long long >
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| numeric_limits< unsigned long long >
| 0
| 0
| ULLONG_MAX
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| numeric_limits< float >
| FLT_MIN
| -FLT_MAX
| FLT_MAX
| FLT_EPSILON
| FLT_MANT_DIG
| FLT_DIG
| FLT_MIN_EXP
| FLT_MIN_10_EXP
| FLT_MAX_EXP
| FLT_MAX_10_EXP
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| numeric_limits< double >
| DBL_MIN
| -DBL_MAX
| DBL_MAX
| DBL_EPSILON
| DBL_MANT_DIG
| DBL_DIG
| DBL_MIN_EXP
| DBL_MIN_10_EXP
| DBL_MAX_EXP
| DBL_MAX_10_EXP
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| numeric_limits< long double >
| LDBL_MIN
| -LDBL_MAX
| LDBL_MAX
| LDBL_EPSILON
| LDBL_MANT_DIG
| LDBL_DIG
| LDBL_MIN_EXP
| LDBL_MIN_10_EXP
| LDBL_MAX_EXP
| LDBL_MAX_10_EXP
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